creating an elevation grid from 3d faces, pick the highest value?

neilcooper33neilcooper33 Global Mapper UserPosts: 14

is there a way when creating an elevation grid from 3d faces (dwg) to pick the highest value always.  ie. i have some roads which bridge over other roads and the elevation grid creates a spikey elevation grid which jumps between the lower and upper road.  I would like the elevation grid to reflect the upper road only, see image below

thanks in advance :)


1.jpg 240.7K

Best Answer

  • sphillipssphillips Posts: 193
    Answer ✓
    Unfortunately I don't believe this is possible. If the TIN surfaces are organised onto individual layers in the source DWG you can split the layers by Feature Description and then grid each layer individually. Then you can organise the layers until they are in the correct order. 


  • neilcooper33neilcooper33 Global Mapper User Posts: 14
    ok, no probs, thanks for the reply
  • CarrickConCarrickCon Posts: 22
    Hi Neil,

    I'm not sure I understand your question fully, but you can easily combine surfaces using the "Combine/Compare Terrain Layers" under the Analysis drop down menu or directly from the icon on the tool bar.

    There are some VERY powerful options in there when combining surfaces. In your case you can select "Maximum Elevation" in the Operation dialogue box and GM will create a combined surface using only the highest surface information. Conversely there is an option to select "Minimum Elevation" when dealing with excavations or in-ground landforms. I often use a combination of Maximum and Minimum to build up a composite of three or four surfaces which have natural topo along with above and below ground design landforms e.g. pit shells, waste rock dumps, process ponds etc.

    Hope this helps. I'm sure if you have a play with the options in there you will find what you are looking for...
  • neilcooper33neilcooper33 Global Mapper User Posts: 14
    many thanks for the info, i'll have a look at these options
Sign In or Register to comment.